Limited flow cup

ABSTRACT

Limited flow cups are provided which deliver a metered amount of fluid to a user during a drinking motion.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Ser. No. 09/711,796,filed Nov. 13, 2000. The subject matter of this patent application isrelated to that of U.S. Ser. No. 09/384,296, filed Aug. 26, 1999, theentire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

This invention relates to limited flow cups.

BACKGROUND

Dysphagia, a condition characterized by difficulty in swallowing foodand liquids, can be present in patients suffering from stroke, headinjury, neurological disorders, and other cognitive and motor problems.It may also occur as a result of aging, disability, or as a transientcondition following some surgeries. As a result of dysphagia, patientsmay also suffer from dehydration and nutritional deficits.

When a person suffering from dysphagia attempts to swallow thin liquids,the bolus may tend to go down the bronchus and into the lungs, causingcoughing, choking and even aspiration, which can lead to pneumonia. Inorder to maintain nutrition and hydration, these patients are sometimesgiven very small volumes, typically about one teaspoon. These smallerboluses can be more readily handled, often without aspiration problems.

Various devices, liquid thickeners and other products have previouslybeen developed to assist patients with dysphagia, but these typically donot allow a fixed volume to be delivered, with a normal drinking motion,without the assistance of a caregiver.

Limited flow drinking cups are designed to provide a fixed, meteredamount of liquid to a user. A typical limited flow cup includes a cupbody having a cover that defines an opening through which fluid canpass. Metering is provided by a three-piece assembly including (a) thecover, (b) a tube that is fixed to the cover at the opening and extendsdownward into the cup body, and (c) a tiny, self-contained metering cupmounted at the lower end of the tube. The metering cup has an open endthat faces in a generally sideways direction. Prior to drinking, the cupbody contains liquid up to a given liquid level, the metering cup isfull of liquid, and the tube is filled with liquid up to the liquidlevel within the cup body. The metering cup and the portion of the tubethat is below the liquid level in the cup body together define ametering chamber having a limited volume. When the user tilts thelimited flow cup to a drinking position, the liquid within the meteringchamber flows through the tube and out through the opening to the user.When the cup body is in the drinking position, the open end of themetering cup generally extends above the liquid level within the cupbody, so that fluid cannot flow into the metering cup. As a result, onlythe volume within the metering chamber is dispensed during a singledrinking motion.

SUMMARY

The present invention features a limited flow cup that has a meteringchamber that is defined by a nested relationship between a pair of cups.The nested arrangement allows the metering chamber to be defined bycomponents that do not include any closed features, such as tubes, andprovides a device that does not include any small or moving parts. Thelack of closed features allows the cups to be readily molded. Ease ofmolding is further facilitated by the simple shape of the cups, whichallows them to release relatively easily from a mold. As a result, thelimited flow cup is generally economical to manufacture, e.g., byinjection molding. The lack of small and moving parts allows the cup tobe easily assembled both during manufacturing and prior to use by theuser or a caregiver, and makes the cup relatively resistant to failureor damage. The cup is also easy for the user to correctly assemble anduse. Additionally, the lack of closed features, which are typicallydifficult to clean, allows the limited flow cup to be kept clean andsanitary, e.g., by simply disassembling the nested cups and washing themin a dishwasher.

In one aspect, the invention features a limited flow cup, including afirst cup, a second cup, in nested relationship with the first cup, anda fluid reservoir, the nested relationship of the first cup and secondcup defining a metering chamber, in fluid communication with thereservoir, constructed to contain an amount of fluid for delivery to auser during a drinking motion, the metering chamber being configured torestrict the amount of fluid delivered to a user when the limited flowcup is tilted during the drinking motion.

Some implementations of this aspect of the invention may include one ormore of the following features.

The metering chamber includes an inlet through which fluid can flow fromthe fluid reservoir to the metering chamber, the inlet being configuredto allow entry of fluid from the reservoir into the metering chamberwhen the limited flow cup is in a first position, and restrict entry offluid from the reservoir into the metering chamber when the limited flowcup is in a second, tilted position. The inlet is positioned so that itwill be above the liquid level in the fluid reservoir when the limitedflow cup is tilted during the drinking motion. The metering chamberincludes a cavity and an elongated fluid passage in fluid communicationwith the cavity.

In some implementations, the first cup includes an outer cup, the secondcup includes an inner cup, disposed within the outer cup, and the innercup defines the fluid reservoir. The cavity is defined by an indentationin a lower surface of the inner cup, and a lower surface of the outercup. The elongated fluid passage is defined by a channel extending intothe inner cup, and a ridge protruding from an inner wall of the outercup. The cavity includes an opening to allow fluid to flow into thecavity from the reservoir. The opening is in a side surface of thecavity, and the opening extends to a lower surface of the inner cup toallow for delivery of essentially all of the liquid in the reservoir.The limited flow cup further includes a cover that sealingly engages therims of the inner and outer cups and defines an opening through whichthe user can drink the liquid. A lower surface of the cover defines anannular channel that, when the cover is in place, is in fluidcommunication with the metering chamber. The cover defines one or moreapertures that communicate between the ambient air and the annularchannel, allowing air to enter the annular channel. The cover furtherdefines a drinking spout, and the aperture(s) allow sufficient air toenter the annular channel so that a user of the limited flow cup ishindered from withdrawing fluid from the limited flow cup by sucking onthe drinking spout.

Alternatively, the limited flow cup further includes an outer cup thatdefines the fluid reservoir, and the first cup and second cup aredisposed within the outer cup. The cavity is defined between bottomwalls of the first and second cups, and the fluid passage is definedbetween side walls of the first and second cups. The first cup includesan opening to allow fluid to flow into the cavity from the reservoir.The opening is in a side surface of the first cup, and the openingextends up the side surface a sufficient distance to allow for deliveryof essentially all of the liquid in the reservoir. The second cupincludes a cover portion that defines an opening through which the usercan drink the liquid. The first cup includes a rim portion thatsealingly engages a peripheral edge of the cover portion. The rimportion also sealingly engages a rim of the second cup. The coverportion and an upper wall of the first cup together define an annularchannel that, when the cover is in place, is in fluid communication withthe metering chamber. The cover portion defines one or more aperturesthat communicate between the ambient air and the annular channel,allowing air to enter the annular channel. The cover portion furtherdefines a drinking spout, and the aperture(s) allow sufficient air toenter the annular channel so that a user of the limited flow cup ishindered from withdrawing fluid from the limited flow cup by sucking onthe drinking spout.

The limited flow cup further includes a pair of regions constructed toreceive a corresponding pair of handles. The limited flow cup furtherincludes a handle constructed to be received by the regions and therebysecurely attached to the limited flow cup. The volume of the meteringchamber is from about 4.5 to 5.5 ml. The volume of the cavity is fromabout 3 to 5 ml. The volume of the elongated fluid passage is less thanabout 25% of the total volume of the metering chamber. The volume of themetering chamber is less than 10% of the volume of the fluid reservoir.The amount of fluid delivered to the user when the fluid reservoir is10% full varies by no more than 25% from the volume delivered when thefluid reservoir is 100% full. The cover defines a headspace volume thatis from about 28% to 40% of the volume of the inner cup. The amountdelivered to the user when the reservoir is 100% full will be less thanor equal to the volume of the metering chamber. The amount delivered tothe user immediately after the reservoir is initially filled by the userwill be less than or equal to the volume of the metering chamber.

The outer cup and inner cup include corresponding structures to preventthe outer cup from being used without the inner cup in nestedarrangement with the outer cup. The outer cup includes an aperture in alower surface of the outer cup, through which liquid will flow if theouter cup is filled with liquid without the inner cup in nestedarrangement with the outer cup. The inner cup includes a plug extendingfrom its lower surface, the plug being positioned to seal the aperturein the lower surface of the outer cup when the inner and outer cups areproperly nested. Alternatively, the aperture in the outer cup includes araised rim, and the inner cup includes a recess that is constructed toseal around the raised rim and over the aperture when the inner andouter cups are properly nested.

In a further aspect, the invention features a limited flow cup,including (a) a first cup, (b) a second cup, in nested relationship withthe first cup, (c) a fluid reservoir, the nested relationship of thefirst cup and second cup defining a metering chamber, in fluidcommunication with the reservoir, constructed to contain an amount offluid for delivery to a user during a drinking motion, and (d) a cover,the cover including an aperture through which the liquid can bedelivered to the user.

Some implementations include one or more of the following features. Thecover is integral with one of the first and second cups. The coverincludes a rim that sealingly engages a rim of one of the first andsecond cups to provide a fluidtight seal. The metering chamber includesan inlet through which fluid can flow from the fluid reservoir to themetering chamber, the inlet being positioned so that it will be abovethe liquid level in the fluid reservoir when the limited flow cup istilted sufficiently to allow fluid to flow from the aperture.

In another aspect, the invention features a limited flow cup fordispensing a limited volume of liquid to a user each time the limitedflow cup is tilted to a drinking position, the limited flow cupincluding: (a) an outer cup, (b) an inner cup, nested within the outercup, for containing a supply of the liquid, and (c) a cover that isconstructed to be sealingly applied to the outer cup and inner cup, thecover including an aperture through which the liquid can be delivered tothe user. The outer cup and inner cup have adjacent spaced surfaces thattogether define a metering chamber that includes a cavity, and anelongated fluid passage in fluid communication between the cavity andthe aperture. The cavity includes an inlet through which fluid can flowfrom the inner cup to the cavity, the inlet being positioned so that itwill be above the liquid level in the inner cup when the inner cup istilted sufficiently to allow fluid to flow from the aperture.

In another aspect, the invention features a limited flow cup fordispensing a limited volume of liquid to a user each time the limitedflow cup is tilted to a drinking position, the limited flow cupincluding: (a) an outer cup for containing a supply of the liquid, (b) amiddle cup, nested within the outer cup, and (c) an inner cup, nestedwithin the middle cup, the inner cup including a cover portion thatincludes an aperture through which the liquid can be delivered to theuser. The middle cup and inner cup have adjacent spaced surfaces thattogether define a metering chamber that includes a cavity, and anelongated fluid passage in fluid communication between the cavity andthe aperture. The cavity includes an inlet through which fluid can flowfrom the outer cup to the cavity, the inlet being positioned so that itwill be above the liquid level in the outer cup when the limited flowcup is tilted sufficiently to allow fluid to flow from the aperture.

In yet a further aspect, the invention features a limited flow cupincluding a pair of nesting inner and outer cups, the inner and outercups being constructed to be nested and disassembled by a user, allowingeasy cleaning, and the nested arrangement of the cups defining a fluidpassage that does not exist when the cups are disassembled.

In some implementations, the inner and outer cups do not include anyclosed features.

Preferred limited flow cups of the invention include an “anti-suck”feature (e.g., the apertures in communication with the annular channel,described above) that impedes the user from circumventing the meteringfunction by sucking fluid out of the cup. Thus, in such cups themetering feature generally cannot be circumvented by applying mouthsuction to the hole in the lid of the cup through which the user drinks.

Some preferred cups do not require the person filling the cup withliquid to follow any special or non-obvious steps, such as filling thecup so that liquid stays below a fill line or mark on the cup, stepswhich may be difficult for caregivers to remember. Such preferred cupsare also designed to meter fluid even when filled to the rim of the cup,while still maintaining an aesthetic cup shape, as will be discussed indetail below. The ability of the cup to function properly when filled tothe rim ensures that a metered volume will be delivered each time theuser drinks from the cup, including the first drink when the cup is atits fullest. This assurance of first-pour functioning is very importantin dysphagia applications, due to the grave consequences that may resultfrom receiving too large a volume of liquid even once.

In some implementations, the assembled cup is generally spill-proof,with only a single metered volume of liquid exiting the cup when it isinadvertently knocked on its side.

Other features and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a cup according to one embodiment of theinvention. FIGS. 1A-1C are front, top and side plan views, respectively.

FIGS. 2 and 2A are cross-sectional views of the cup of FIG. 1, takenalong line A-A of FIG. 1A. In FIG. 2, the cup is in an upright position.In FIG. 2A the cup is shown in a tipped, drinking position.

FIGS. 3, 3A and 3B are exploded perspective views of the cup of FIG. 1,taken from different angles.

FIGS. 4 and 4A are schematic cross-sectional views illustratingalternate structures for preventing the use of the outer cup as adrinking cup.

FIG. 5 is a perspective view of a cup according to an alternativeembodiment of the invention. FIG. 5A is a cross-sectional view of thecup, taken along line A-A in FIG. 5. FIG. 5B is a partially explodedview of the cup of FIG. 5.

FIG. 6 is a perspective view of an outer component of the cup of FIG. 5.FIG. 6A is a side view of the outer component. FIG. 6B is across-sectional view of the outer component, taken along line B-B inFIG. 6A.

FIG. 7 is a perspective view of a middle component of the cup of FIG. 5.FIG. 7A is a side view of the middle component. FIG. 7B is across-sectional view of the outer component, taken along line B-B inFIG. 7A.

FIG. 8 is a perspective view of an inner/lid component of the cup ofFIG. 5. FIG. 8A is a side view of the inner/lid component. FIG. 8B is across-sectional view of the outer component, taken along line B-B inFIG. 8A.

FIGS. 9-9C are, respectively, a perspective view, a top view, an endview and a side view of a handle for use with the cup of FIG. 5.

DETAILED DESCRIPTION

Referring to FIG. 1, limited flow cup 10 includes an outer cup 12including a generally cylindrical side wall 54 and a generally flatbottom surface 52 (FIG. 3). A pair of handles 16 extend from side wall54. A cover 14 is constructed to be sealingly attached to the outer cup12. As shown in FIGS. 1A and 1B, the cover 14 includes a drinking spout18 having an aperture 20 through which a user of the cup can sip aliquid. The cover also includes a vent hole 22 to allow air to enter thecup as fluid is depleted and thereby allows liquid to flow out of theinner cup unimpeded, and three “anti-suck” holes 24, the function ofwhich will be discussed below.

Referring to FIG. 3, the limited flow cup 10 further includes agenerally cylindrical inner cup 26 that is slightly smaller in outerdiameter than the inner diameter of the outer cup 12, and slightlyshorter than outer cup 12, so that the inner cup 26 can be receivedwithin the outer cup 12 in nested engagement as shown in FIG. 2. Aclearance of 0.005 to 0.010 inches would ensure that the cups could beeasily nested and un-nested and at the same time ensure that very littleliquid-holding volume is created between the cups. The inner cup 26 fitssnugly within the outer cup 12, and defines a reservoir 38 for holding aliquid. The inner and outer cups include structural features thattogether define a metering chamber when the cups are nested, as will bediscussed below.

As shown in FIG. 3, the inner cup 26 includes a generally flat bottomsurface 44 and a generally cylindrical side wall 48, having a locallyflat portion 49. A disc-shaped cavity 42 is formed by an indentation 64in bottom surface 44. A channel 46, defined by a diagonally cut groovein the inner cup 26, defines a triangular volume extending from thecavity 42 up the outer side wall 48 of the inner cup. (Seen from above,in FIGS. 3A and 3B, the cavity 42 and channel 46 look like a protrusion42′ and a ridge 46′, respectively.)

As shown in FIG. 3B, the inner surface of outer cup 12 includes anelongated generally triangular ridge 50 that extends along part of thebottom surface 52 and extends up the inner surface of side wall 54 ofthe outer cup 12.

When the inner cup 26 and outer cup 12 are nested (as shown in FIGS.2-2A), the cavity 42 is closed from below by the generally flat bottomsurface 62 of the outer cup 12. Ridge 50 nests within channel 46 (FIG.3), filling most of the volume of the channel, i.e., the width of theridge is nearly that of the channel, so that a seal will be formedbetween the ridge and channel. The ridge 50 is slightly shorter than thedepth of the channel, so that an elongated fluid passage 56 (FIG. 2) isdefined between the “hypotenuse” or top surface 59 (FIG. 3B) of theridge and the upper wall 58 of the channel. Elongated fluid passage 56extends diagonally from the cavity 42, with which it is in fluidcommunication, to the rim 60 of the nested inner and outer cup assembly.The elongated fluid passage 56 ends in an open terminus 57 at rim 60.The cavity 42 communicates with the inside of inner cup 26 by way of anaperture 66 in the wall 68 of cavity 42 that is located diametricallyopposite the inlet of elongated fluid passage 56.

In addition to defining the metering chamber, the engagement of ridge 50with channel 46 self-aligns the inner and outer cups, so that thelimited flow cup is easy for a caregiver or patient to assemblecorrectly.

When the cup is in its upright position, shown in FIG. 2, liquid 40flows into cavity 42 through aperture 66, until the cavity 42 is fulland liquid is also present in the elongated fluid passage 56 up to theliquid level L. The cavity 42 and elongated fluid passage 56 togetherdefine a metering chamber. The total volume of liquid that is in themetering chamber when the device is tipped to a drinking position (FIG.2A) is the volume of liquid that will be delivered to the user throughaperture 20. The volume delivered to the user will vary slightly as theliquid level in the cup drops, due to the reduced volume of liquid thatwill be present in the elongated fluid passage 56. The volume of thecavity is much larger than that of the elongated fluid passage(generally the ratio of the volume of the elongated fluid passage tothat of the cavity is about 1:4 to 1:10). As a result, the volume of thecavity dominates, and the user will receive essentially the same amountof liquid regardless of the level of fluid in the elongated passage,which will be reduced as the liquid in the cup is depleted. It is alsonoted that the user may not receive the entire volume present in themetering chamber, depending on the angle to which the user tips thedevice (e.g., it may be necessary to tip the device well beyond theangle shown in FIG. 2A (generally to about 90 degrees from the positionshown in FIG. 2) to receive the entire volume in the metering chamber.)

As discussed above, cover 14 includes a drinking spout 18. Spout 18 islocated diametrically opposite the cavity 42, to properly orient the cupas will be discussed below. The spout extends relatively high above theupper surface of the cover, and joins with the cover in a smoothlycurved surface, to allow the user to drink from the cup without tiltinghis head back, i.e., to drink in what is sometimes referred to as a“chin tuck” position. This position is generally thought to be a saferdrinking position for patients suffering from dysphagia. The cover 14 isalso quite tall, relative to the height of the inner and outer cups, forreasons which will be explained below.

Cover 14 also includes a generally cylindrical outer sleeve 28 that iscoextensive with the outer surface of the cover and is dimensioned toengage rim 30 of cup body 12 in an interference engagement. Cover 14also includes, extending downwardly from its inner top surface, agenerally cylindrical inner sleeve 32 that is generally coaxial with theouter sleeve 28. Inner sleeve 32 is dimensioned to fit within andsealingly engage the inner wall 34 of inner cup 26 to provide afluid-tight seal. To allow the cover to be easily snapped onto thenested inner and outer cups, and to facilitate fluid-tight sealing, thecover is preferably formed of a resilient material.

An annular channel 65 is defined between the outer wall 67 of the coverand the inner sleeve 32 (see FIGS. 2 and 3). This annular channel 65 isin fluid communication with the open terminus 57 of the elongated fluidpassage 56, and also with aperture 20 in the spout 18. Thus, duringdrinking (FIG. 2A), fluid flows from the elongated fluid passage 56,into the annular channel 65, and through aperture 20 to the user. Asshown in FIG. 3, a portion 31 of the inner sleeve 32 is flattened, toprovide a relatively large volume in the area of the annular channelthat is adjacent terminus 57, allowing good flow of fluid to theaperture 20. The flattened portion 31 of the inner sleeve 32 is alsogeometrically similar to a flat surface 29 (FIG. 3B) on the inside ofthe inner cup 26, adjacent to the open terminus 57 of the elongatedfluid passage 56, thereby allowing surface 31 of the inner sleeve 32 toseal to surface 29 of the inner cup 26.

Annular channel 65 also communicates with “anti-suck” holes 24. The“anti-suck” holes 24 allow air to pass into the annular channel 65 inthe event that the user sucks on the spout 18, in an attempt to aspirateliquid from the device without tilting the device to a drinking positionand thereby activating the limited flow function (discussed below). The“anti-suck” holes 24 prevent the pressure in the annular channel 65 frombeing lowered sufficiently for fluid to be drawn up into the spout 18,thereby preventing the user from circumventing the limited flow functionof the cup. It is preferred that the cover include a plurality of“anti-suck” holes, as shown, rather than a single hole, because it isunlikely that a user would inadvertently cover multiple holes with afinger during use of the cup.

Preferably, the inner and outer cups and the cover are formed byinjection molding. Suitable materials for the inner and outer cupinclude thermoplastic polymers such as polyethylene, polypropylene,polyamides, such as Nylon, and polycarbonate. Thermosets may also beused. Suitable materials for the cover include relatively compliantthermoplastic polymers, such as polypropylene, polyethylene,polyurethanes, plasticized polyvinyl chloride (PVC), and thermoplasticelastomers (TPEs).

When the cup is to be used, the inner cup is nested within the outercup, and the inner cup is filled with a liquid to or above a fill line(not shown) on its inner wall 34. (The fill line indicates the amount ofliquid that should be added in order for the cup to initially containthe advertised volume of the cup, e.g., 8 fluid ounces.) The inner cup26 can be filled up to its rim, if desired, without any problems inmetering of the liquid 40, for reasons that will be discussed below. Thefill line is preferably ⅛ to ⅜ inch below the rim, so that the cup maybe filled with its advertised volume and the lid snapped in placewithout spilling liquid from the cup. Once the inner cup is filled, thecover 14 is then snapped onto the cup assembly, so that the cover andthe rims of the inner and outer cups are in sealing engagement. Asshown, e.g., in FIG. 3B, the top surface 59 of the ridge 50 is slightlyconvex, as is the corresponding upper wall 58 of channel 46. Thecurvature of surface 59 allows surface 59 to be relatively vertical nearthe rim of outer cup 12, and, similarly, the curvature of wall 58 allowswall 58 to be relatively vertical near the rim of inner cup 26. Thesevertical surfaces, and the relatively small interruption of thecircularity of the rims of the inner and outer cups facilitates thesealing engagement of the inner and outer sleeves of the cover 14 withthe rims of the cups. To drink from the device, the user places thespout 18 to his lips and tilts the cup in a normal drinking manner.

When the user tips the cup to a drinking position, as shown in FIG. 2A,the volume of liquid in the metering chamber is delivered to the userthrough aperture 20. As the cup is tipped to a drinking position, liquidflows within the inner cup 26 so that level L′ remains horizontal. Theinner cup and cover are dimensioned, and the cavity 42 and aperture 66are oriented, so that before the angle of tilt of the cup is such thatliquid will flow out of the spout 18 (typically at least about 30degrees from the horizontal) the aperture 66 will be exposed above theliquid level L′ in the inner cup 26, as shown in FIG. 2A. Because theaperture 66 is above the liquid level L′, liquid will not flow intoaperture 66 when the cup is tilted further for drinking, and thus theuser will receive only the volume of liquid in the metering chamber, asdiscussed above. To drink more liquid, the user must return the cup toits upright (or nearly upright) position, allowing the user time toswallow the predetermined volume of liquid. Because spout 18 is locateddiametrically opposite the cavity 42, as discussed above, the user willalways orient the cup so that the aperture 66 will be above the liquidlevel during drinking, as shown in FIG. 2A.

It is important that the limited flow cup perform its metering functionthe first time (and every subsequent time) that the cup is used, andthat it perform the metering function regardless of how full the innercup 26 is filled. In other words, it is important that the limited flowfunction of the cup not be circumvented by over-filling the inner cup26, and that the amount of liquid dispensed to the user never exceed themaximum volume of the metering chamber. Preferably, the amount of liquiddispensed to the user is approximately same (e.g., vary by no more than25%) whether the inner cup is 10% full or 100% full.

In order for the metering function to be performed every time the cup isused, regardless of the fill level, two conditions must be met: (a)there must be a sufficient volume of air within the cup to allow theliquid to flow to the position shown in FIG. 2A when the cup is tilted,and (b) there must be sufficient open area in the cover on the spoutside to allow all of the liquid in the cup (up to the maximum volumethat the inner cup can contain) to be below line L′ in FIG. 2A when thecup is inclined at an angle at which fluid first begins to flow out ofthe aperture 20.

The first condition can be met by making the cover 14 is quite tall,relative to the height of the inner and outer cups, as shown in thefigures. As a result of the height of the cover, the inner sleeve 32 andwall 36 together define a relatively large open volume or “headspace”that cannot be filled with liquid when the user fills the inner cup.This headspace allows the liquid to be displaced within the cup as shownin FIG. 2A when the cup is tilted (i.e., allows the cup to meetcondition (a), above). For the cover geometry shown in FIGS. 2-2A, thevolume of the headspace defined by the cover is generally about 28% to40% of the volume of the inner cup.

However, the total headspace volume required to satisfy both conditionswill depend upon the geometry of the cover, e.g., the total volumerequired will be less if the volume defined by the drinking spout (thevolume on the side of the cup into which the liquid flows when the cupis tilted to drink) is increased. In order to satisfy condition (b), itis important that, of the total volume of the headspace, a sufficientamount is disposed on the side of the cup into which the liquid flowswhen the cup is tilted to drink so that the level of the liquid willnever be above line L′ when the cup is tilted to the angle at whichliquid will begin to flow out of aperture 20. Also, for a givenheadspace, the higher the spout extends above the cover, the greaterwill be the tip angle required before liquid will flow from the aperture20. The extra volume created by an extended drinking spout is createdmostly in the annular volume, where it does not alter the fluid leveldynamics in the volume enclosed by the inner cup and the headspaceinside the lid's inner partition.

For a cup having an advertised volume of 8 fluid ounces, the preferreddimensions of the cup are as follows: the inner diameter of the innercup 26 is from about 3.0 to 3.5 inches, the diameter of the inner sleeveof the cover is the same as the inner diameter of the inner cup 26, theheight of the inner cup is from about 1.5 to 2.5, the height of thecover (exclusive of the spout) is from about 0.75 to 1.25 inches, andthe height of the spout above the top of the cover is about 0.75 to 1.25inches. The volume of the cup may be altered, e.g., by scaling alldimensions proportionally.

Other embodiments are within the scope of the following claims.

It is generally desirable to prevent the user of the limited flow cup,or a caregiver, from circumventing the metering feature of the limitedflow cup by using the outer cup 12 alone, without the inner cup 26. Thismay be accomplished in a variety of ways, as will be apparent to thoseskilled in the art. Two examples are illustrated in FIGS. 4 and 4A. Asshown in FIG. 4, the outer cup 12 may include an aperture 100 in itslower surface, and the inner cup 26 may include a plug 102 that sealsthe aperture 100 when the cups are properly nested. Alternatively, asshown in FIG. 4A, the outer cup 12 may include a bore 104 having a rim106, and the inner cup 26 may include an annular recess 108 that isconstructed to fit sealingly over the rim 106.

For example, the cavity need not be disc-shaped, but could be square,rectangular, or any other desired shape. The ridge in the outer cup canbe omitted, and the channel defined by a groove in the inner cup and acylindrical inner wall of the outer cup. Also, while the ridge is shownand described as having a slightly curved “hypotenuse”, the ridge may bemore triangular in shape. Many other alterations of the structuralfeatures of the inner and outer cup may be made, provided that thenested arrangement of the inner and outer cup defines the meteringchamber.

The cup has been shown as having two handles. However, in otherembodiments the cup may have a single handle or no handle.

While the cover has been shown and discussed as being relatively tall,and having a tall, curved spout, many other cover designs may be used.Suitable cover geometries will depend upon the volume of the cup and theapplication in which it will be used, as will be readily understood bythose skilled in the art.

The cup may be used in many applications, other than by dysphagiasufferers, e.g., as a travel coffee mug, as an infant “dripless” cup, oras a disposable container for beverages such as nutritional drinks. Whenthe cup is used to dispense hot beverages, the double-walledconstruction may afford a degree of thermal insulation. Depending on theapplication, the volume of the cavity may vary widely, e.g., from 1 to20 ml.

An alternative limited flow cup 110 is shown in FIGS. 5-5B. As shown inFIG. 5B, limited flow cup 110 includes an outer cup 112 and, nestedwithin outer cup 112, an inner cup 111 and a middle cup 127. Inner cup111 defines a cylindrical body 160, and a cover portion 114 thatincludes a drinking spout 118 having an aperture 120 through which auser of the cup can sip a liquid. The cover portion 114 also includes apair of anti-suck vents 122 (FIG. 5B), which function, as describedabove, to prevent a user from aspirating liquid from the device withouttilting the device to a drinking position. Middle cup 127 defines acylindrical body 162 and a rim portion 115.

Middle cup 127 is configured to be received between the outer cup 112and the inner cup 111 in nested engagement. In this embodiment, it isthe cylindrical bodies 160, 162 of the inner and middle cups thatinclude structural features that together define a metering chamber whenthe cups are nested. The manner in which the metering chamber is definedby the inner and middle cups will be discussed in detail below. Thefluid is retained in the outer cup, with a metered amount beingdelivered to the metering chamber through an opening 146 in the middlecup.

As shown in FIG. 5A, the nested arrangement of the inner cup 111 andmiddle cup 127 defines a metering chamber 130. Metering chamber 130includes a cavity 131 defined between the lower surface 132 of thebottom wall 134 of inner cup 111 and the upper surface 136 of the bottomwall 138 of the middle cup 127. Metering chamber 130 also includes afluid passage 140 that is defined between the side walls 142 and 144 ofthe inner cup 111 and middle cup 127, respectively, and which providesfluid communication between the cavity 131 and the aperture 120. Sidewalls 142 and 144 are angled in the area of the fluid passage 140, sothat the fluid passage extends diagonally from the cavity 131 toward theaperture 120. As in the embodiment shown in FIGS. 1-3B, the cavity 131is positioned diametrically opposite to aperture 120, to properly orientthe cup. Preferably, side walls 142 and 144 extend at an angle of about4 to 6 degrees from the vertical (the axis of the outer cup).

The inner wall 155 of the cover portion 114, and the upper wall 156 ofthe middle cup 127 define an annular channel 158, as shown in FIG. 5A.As discussed above with respect to FIGS. 1-3B, this annular channelprovides good fluid flow from the fluid passage 140 to aperture 120.

Features of the outer, middle and inner cups will now be described infurther detail.

Referring to FIGS. 6-6B, the outer cup 112 includes a generallycylindrical side wall 154 and a generally flat bottom surface 152. Theside wall 154 includes a pair of channels 164, dimensioned to receivehandles 116, as indicated in FIG. 5B, and a pair of retaining members166, which retain the handles 116 in channels 164. The handles 116, oneof which is shown in detail in FIGS. 9-9C, each include an interlockingmember 163 that is configured to fit within channel 164 and underretaining member 166. An open area 167 is provided between theinterlocking member 163 and the body of the handle 169 to receive theretaining member 166. The handles also include a rib 165 that isconfigured to fit over the rim 119 of the outer cup, as shown in FIG. 5.To attach a handle, the user slides the interlocking member 163 up thechannel 164 and under the retaining member 166, until the rib 165 snapsin place over the rim 119. Once attached, the handles are held securelyin place and are difficult to remove so that they will not be removedinadvertently.

Referring to FIGS. 7-7B, the middle cup 127 includes an opening 146,discussed above, that is positioned to allow fluid to flow from theouter cup 112 into the metering chamber 130. Opening 146 is configuredso that, when the cup is tipped by the user during drinking, only alimited amount of liquid will flow into the metering chamber before theliquid level of the cup is above the intersection of the opening 146 andthe inner cup 111.

As shown in FIG. 7, the middle cup 127 also includes a channel 153 that,with the side wall 142 of the inner cup, defines the fluid passage 140.The remainder of the side wall 144 of the middle cup 127 correspondsclosely to the outer diameter of the inner cup 111, for a snug nestedfit. This snug nested fit prevents fluid from flowing between the innerand middle cups except in the area of the fluid passage 140.

Again referring to FIGS. 7-7B, the rim 115 of middle cup 127 includes avent groove 150 that, when the rim 115 is sealingly engaged with the rim119 of the outer cup, as discussed below, provides an opening thatallows air to enter the outer cup, preventing a vacuum from beingcreated as liquid is dispensed. As shown in FIG. 5, when the limitedflow cup is assembled the vent opening is diametrically opposite theaperture 120 to reduce spillage.

Referring to FIGS. 8-8B, the inner cup 111 includes a body 160 and acover portion 114, as discussed above. The cover portion 114 includes asealing rim 117 that is constructed to sealingly engage rim 115 ofmiddle cup 127. Rim 115 is constructed, in turn, to sealingly engage rim119 of outer cup 112, as shown in FIG. 5A The rims engage each other bya snug interference fit, providing a fluid-tight seal and preventing thecup assembly from inadvertantly coming apart during use. A tab 121extends from rim 117, to allow the cover portion to be easily disengagedfrom the middle cup for cleaning and filling of the limited flow cup.The cover portion also is configured to define the annular channel 158,as discussed above.

When the user purchases the cup, the handles are not attached to theouter cup, allowing the user to choose whether to use one left- orright-handed handle, or two handles. Thus, before the first use of thecup, the user attaches one or both of the handles, by slidinginterlocking member 163 of the handle 116 into channel 164 on the outercup 112 and under retaining member 166, as described above.

To use the cup, the user fills the outer cup to the level indicated byfill line 148 (FIG. 5A). The user then assembles the outer, middle andinner cups, snapping the rims together securely. Generally, the userassembles the cups so that the aperture 120 of spout 118 is at roughly a3 O'Clock position around the circumference of the outer cup, relativeto the handles at 12 O'Clock. However, in this embodiment the spout maybe positioned in any desired circumferential orientation relative to thehandles (so long as the rib 165 of the handles does not interfere withthe vent opening). To drink from the device, the user places the spout118 to his lips and tilts the cup in a normal drinking manner.

When the user tips the cup to a drinking position, the volume of liquidin the metering chamber is delivered to the user through aperture 120.As the cup is tipped to a drinking position, liquid flows within theouter cup 112 so that the liquid level remains horizontal. The inner cupand cover are dimensioned, and the cavity 131 and aperture 120 areoriented, so that before the angle of tilt of the cup is such thatliquid will flow out of the spout 118 (typically at least about 30degrees from the horizontal) the open portion of aperture 146 (theportion below the intersection of aperture 146 with inner cup 111) willbe exposed above the liquid level in the outer cup 112. Because theaperture 146 is above the liquid level in the outer cup, liquid will notflow into aperture 146 when the cup is tilted further for drinking, andthus the user will receive only the volume of liquid in the meteringchamber, as discussed above. To drink more liquid, the user must returnthe cup to its upright (or nearly upright) position, allowing the usertime to swallow the predetermined volume of liquid. Because spout 118 islocated diametrically opposite the cavity 131, as discussed above, theuser will always orient the cup so that the aperture 146 will be abovethe liquid level during drinking.

1. A limited flow cup, comprising a first cup, a second cup, in nestedrelationship with the first cup, and a fluid reservoir, the nestedrelationship of the first cup and second cup defining a meteringchamber, in fluid communication with the reservoir, constructed tocontain an amount of fluid for delivery to a user during a tiltingmotion, the metering chamber being configured to restrict the amount offluid delivered to a user when the limited flow cup is tilted tosubstantially the volume of the metering chamber when the fluidreservoir contains an amount of fluid significantly greater than thevolume of the metering chamber.
 2. The limited flow cup of claim 1wherein the metering chamber includes an inlet through which fluid canflow from the fluid reservoir to the metering chamber, the inlet beingconfigured to allow entry of fluid from the reservoir into the meteringchamber when the limited flow cup is in a first position, and restrictentry of fluid from the reservoir into the metering chamber when thelimited flow cup is in a second, tilted position.
 3. The limited flowcup of claim 2 wherein the inlet is positioned so that it will be abovethe liquid level in the fluid reservoir when the limited flow cup istilted.
 4. The limited flow cup of claim 1 wherein the first cupcomprises an outer cup, the second cup comprises an inner cup, disposedwithin the outer cup, and the inner cup defines the fluid reservoir. 5.The limited flow cup of claim 4 wherein said metering chamber comprisesa cavity and an elongated fluid passage in fluid communication with thecavity.
 6. The limited flow cup of claim 5 wherein the cavity is definedby an indentation in a lower surface of the inner cup, and a lowersurface of the outer cup.
 7. The limited flow cup of claim 5 wherein theelongated fluid passage is defined by a channel extending into the innercup, and a feature protruding from an inner wall of the outer cup. 8.The limited flow cup of claim 5 wherein the cavity includes an openingto allow fluid to flow into the cavity from the reservoir.
 9. Thelimited flow cup of claim 8 wherein the opening is in a side surface ofthe cavity, and the opening extends to a lower surface of the inner cupto allow for delivery of essentially all of the liquid in the reservoir.10. The limited flow cup of claim 4 further comprising a cover thatsealingly engages the rims of the inner and outer cups and defines anopening through which the user can drink the liquid.
 11. The limitedflow cup of claim 10 wherein a lower surface of the cover defines anannular channel that, when the cover is in place, is in fluidcommunication with the metering chamber.
 12. The limited flow cup ofclaim 11 wherein the cover defines one or more apertures thatcommunicate between the ambient air and the annular channel, allowingair to enter the annular channel.
 13. The limited flow cup of claim 12wherein the cover further defines a drinking spout, and the aperture(s)allow sufficient air to enter the annular channel so that a user of thelimited flow cup is hindered from withdrawing fluid from the-limitedflow cup by sucking on the drinking spout.
 14. The limited flow cup ofclaim 1 wherein the limited flow cup further comprises an outer cup thatdefines the fluid reservoir, and the first cup and second cup aredisposed within the outer cup.
 15. The limited flow cup of claim 14wherein said metering chamber comprises a cavity and an elongated fluidpassage in fluid communication with the cavity.
 16. The limited flow cupof claim 15 wherein the cavity is defined between bottom walls of thefirst and second cups.
 17. The limited flow cup of claim 15 wherein thefluid passage is defined between side walls of the first and secondcups.
 18. The limited flow cup of claim 16 wherein the first cupincludes an opening to allow fluid to flow into the cavity from thereservoir.
 19. The limited flow cup of claim 18 wherein the opening isin a side surface of the first cup, and the opening extends up the sidesurface a sufficient distance to allow for delivery of essentially allof the liquid in the reservoir.
 20. The limited flow cup of claim 14wherein the second cup includes a cover portion that defines an openingthrough which the user can drink the liquid.
 21. The limited flow cup ofclaim 20 wherein the first cup includes a rim portion that sealinglyengages a peripheral edge of the cover portion.
 22. The limited flow cupof claim 21 wherein the rim portion also sealingly engages a rim of thesecond cup.
 23. The limited flow cup of claim 21 wherein the coverportion and an upper wall of the first cup together define an annularchannel that, when the cover is in place, is in fluid communication withthe metering chamber.
 24. The limited flow cup of claim 23 wherein thecover portion defines one or more apertures that communicate between theambient air and the annular channel, allowing air to enter the annularchannel.
 25. The limited flow cup of claim 24 wherein the cover portionfurther defines a drinking spout, and the aperture(s) allow sufficientair to enter the annular channel so that a user of the limited flow cupis hindered from withdrawing fluid from the limited flow cup by suckingon the drinking spout.
 26. The limited flow cup of claim 1 or 14 furthercomprising a pair of regions constructed to receive a corresponding pairof handles.
 27. The limited flow cup of claim 26 further comprising ahandle constructed to be received by the regions and thereby securelyattached to the limited flow cup.
 28. The limited flow cup of claim 1 or14 wherein the volume of said metering chamber is from about 4.5 to 5.5ml.
 29. The limited flow cup of claim 5 or 15 wherein the volume of saidcavity is from about 3 to 5 ml.
 30. The limited flow cup of claim 5 or15 wherein the volume of said elongated fluid passage is less than about25% of the total volume of the metering chamber.
 31. The limited flowcup of claim 1 wherein the volume of the metering chamber is less than10% of the volume of the fluid reservoir.
 32. The limited flow cup ofclaim 1, wherein the amount of fluid delivered to the user when thefluid reservoir is 10% full varies by no more than 25% from the volumedelivered when the fluid reservoir is 100% full.
 33. The limited flowcup of claim 10 wherein the cover defines a headspace volume that isfrom about 28% to 40% of the volume of the inner cup.
 34. The limitedflow cup of claim 1 wherein the amount delivered to the user when thereservoir is 100% full will be less than or equal to the volume of themetering chamber.
 35. The limited flow cup of claim 1 wherein the amountdelivered to the user immediately after the reservoir is initiallyfilled by the user will be less than or equal to the volume of themetering chamber.
 36. The limited flow cup of claim 4 wherein the outercup and inner cup include corresponding structures that prevent theouter cup from being used without the inner cup in nested arrangementwith the outer cup.
 37. The limited flow cup of claim 36 wherein theouter cup includes an aperture in a lower surface of the outer cup,through which liquid will flow if the outer cup is filled with liquidwithout the inner cup in nested arrangement with the outer cup.
 38. Thelimited flow cup of claim 37 wherein the inner cup includes a plugextending from its lower surface, the plug being positioned to sealthe-aperture in the lower surface of the outer cup when the inner andouter cups are properly nested.
 39. The limited flow cup of claim 37wherein the aperture in the outer cup includes a raised rim, and theinner cup includes a recess that is constructed to seal around theraised rim and over the aperture when the inner and outer cups areproperly nested.
 40. A limited flow cup, comprising a first cup, asecond cup, in nested relationship with the first cup, a fluidreservoir, the nested relationship of the first cup and second cupdefining a metering chamber, in fluid communication with the reservoir,constructed to contain an amount of fluid for delivery to a user duringa drinking motion, and a cover, the cover including an aperture throughwhich the liquid can be delivered to the user.
 41. The limited flow cupof claim 40 wherein the cover is integral with one:of the first andsecond cups.
 42. The limited flow cup of claim 40 wherein the coverincludes a rim that sealingly engages a rim of one of the first andsecond cups to provide a fluidtight seal.
 43. The limited flow cup ofclaim 40 wherein the metering chamber includes an inlet through whichfluid can flow from the fluid reservoir to the metering chamber, theinlet being positioned so that it will be above the liquid level in thefluid reservoir when the limited flow cup is tilted sufficiently toallow fluid to flow from the aperture.
 44. A limited flow cup fordispensing a limited volume of liquid to a user each time the limitedflow cup is tilted to a drinking position, the limited flow cupcomprising: an outer cup, an inner cup, nested within the outer cup, forcontaining a supply of the liquid, and a cover that is constructed to besealingly applied to the outer cup and inner cup, the cover including anaperture through which the liquid can be delivered to the user, theouter cup and inner cup having adjacent spaced surfaces that togetherdefine a metering chamber that includes a cavity, and an elongated fluidpassage in fluid communication between the cavity and the aperture, thecavity including an inlet through which fluid can flow from the innercup to the cavity, the inlet being positioned so that it will be abovethe liquid level in the inner cup when the inner cup is tiltedsufficiently to allow fluid to flow from the aperture.
 45. (canceled)46. A limited flow cup for dispensing a limited volume of liquid to auser each time the limited flow cup is tilted to a drinking position,the limited flow cup comprising: an outer cup for containing a supply ofthe liquid, a middle cup, nested within the outer cup, and an inner cup,nested within the middle cup, the inner cup including a cover portionthat includes an aperture through which the liquid can be delivered tothe user, the middle cup and inner cup having adjacent spaced surfacesthat together define a metering chamber that includes a cavity, and anelongated fluid passage in fluid communication between the cavity andthe aperture, the cavity including an inlet through which fluid can flowfrom the outer cup to the cavity, the inlet-being positioned so that itwill be above the liquid level in the outer cup when the limited flowcup is tilted sufficiently to allow fluid to flow from the aperture. 47.(canceled)
 48. A limited flow cup comprising a pair of nesting inner andouter cups, the inner and outer cups being constructed to be nested anddisassembled by a user, allowing easy cleaning, and the nestedarrangement of the cups defining a fluid passage that does not existwhen the cups are disassembled.
 49. The limited flow cup of claim 48wherein the inner and outer cups do not include any closed features. 50.The limited flow cup of claim 44 wherein the cavity is defined by anindentation in a lower surface of the inner cup, and a lower surface ofthe outer cup.
 51. The limited flow cup of claim 44 wherein theelongated fluid passage is defined by a channel extending into the innercup, and a feature protruding from an inner wall of the outer cup. 52.The limited flow cup of claim. 44 wherein the inlet is in a side surfaceof the cavity, and the inlet extends to a lower surface of the inner cupto allow for delivery of essentially all of the liquid in the reservoir.53. The limited flow cup of claim 44 wherein a lower surface of thecover defines an annular channel that, when the cover is in place, is influid communication with the metering chamber.
 54. The limited flow cupof claim 53 wherein the cover further defines a drinking spout, and oneor more apertures that communicate between the ambient air and theannular channel, allowing air to enter the annular channel, theaperture(s) allowing sufficient air to enter the annular channel so thata user of the limited flow cup is hindered from withdrawing fluid fromthe limited flow cup by sucking on the drinking spout.
 55. A method ofdelivering a metered dose of fluid to a patient, comprising: providing alimited flow cup, comprising a first cup, a second cup, in nestedrelationship with the first cup, and a fluid reservoir, the nestedrelationship of the first cup and second cup defining a meteringchamber, in fluid communication with the reservoir, constructed tocontain an amount of fluid for delivery to a user during a drinkingmotion, the metering chamber being configured to restrict the amount offluid delivered to a user when the limited flow cup is tilted during thedrinking motion, the cup further comprising a cover that defines anopening through which the user can drink the liquid; delivering a fluidto the fluid reservoir; and